Deployment of different physical layer protocols in a radio access network

Abstract

This invention relates to a method, a system, a base station, a base station hub (41) and software applications for data transmission between at least one base station (42-1, 42-2) and a radio network controller (40) in a radio access network, said method comprising operating a first-type physical layer protocol (46) for a transmission of said data between said at least one base station (42-1, 42-2) and a base station hub (41); operating a second-type physical layer protocol (47) for a transmission of said data between said base station hub (41) and said radio network controller (40); wherein said data comprises user data (340) that is transmitted between said radio network controller (40) and said at least one base station (42-1, 42-2) via said base station hub (41); and wherein said at least one base station (42-1, 42-2) performs at least base band processing for signals that are transmitted via a radio interface (7) and represent said user data (340).

Description

FIELD OF THE INVENTION [0001] This invention relates to a method, a system, a base station, a base station hub and software applications for data transmission between at least one base station and a radio network controller in a radio access network. BACKGROUND OF THE INVENTION [0002] The Universal Mobile Telecommunications System (UMTS) is a third-generation broadband wireless transmission system for text, digitized voice, video, and multimedia at data rates up to 2 megabits per second that offers a consistent set of services to mobile computer and phone users. [0003] The network elements of a UMTS 1 are illustrated in FIG. 1. The network elements are functionally grouped into the radio access network (UMTS Terrestrial Radio Access Network, UTRAN) 11 that handles all radio-related functionality, and the Core Network (CN) 12, which is responsible for switching and routing calls and data connections to external networks 2, for instance circuit-switched networks 20 such as PSTN and IS...

AI Technical Summary

Benefits of technology

[0030] The introduction of the base station hub according to the present invention allows for the use of at least two different physical layer protocols between said radio network controller and said base station and thus increases the degrees of freedom in choosing appropriate and efficient transmission technologies for the operator. For instance, an operator may choose to use Ethernet as first-type physical layer protocol between said base station and said base station hub instead of the SDH / PDH links commonly used in radio access networks, which vastly contributes to reduce the cabling costs, in particular if already installed Ethernet infrastructure networks can be re-used. The use of different physical layer protocols between radio network controller and base station hub on the one hand and base station hub and base station on the other hand also allows to shift complex transmission- and transport-related functionality from the base station into the base station hub, so that the base stations according to the present invention become less complex, cheaper and smaller, and so that functionality is more efficiently used in the base station hub.

[0036] The use of an Ethernet network for data transmission between the base station and the base station hub may be particularly advantageous because existing Ethernet cables and networks, for instance in-house infrastructure of a Local Area Network (LAN), may be easily reused. The use of Ethernet may allow to reduce the size of said base station, because an explicit transport block housing interfaces for the PDH or SDH links that are frequently used in prior art for the link between the radio network controller and the base station is no longer required. Ethernet provides support for data rates of 10, 100, 1000 and 10000 Mbit / s that are all easily interoperable.

[0039] According to an embodiment of the present invention, said data is transmitted between a plurality of base stations and said radio network controller, and said base station hub operates said first-type physical layer protocol for a transmission of said data between said base station hub and said plurality of base stations. Said plurality of base stations may for instance be connected to the base station hub via an Ethernet network. When several base stations are connected to said base station hub, said base station hub may concentrate functionality that in prior art is provided by said base stations, so that the complexity of said base stations may be reduced. Said functionality may refer to both hardware and software of said base stations. For instance, said base station hub may terminate management protocols towards the radio network controller and use a proprietary management protocol for the management of its associated base stations. For the radio network controller, the base station hub with its associated base station then may appear as a single base station.

[0045] According to an embodiment of the first aspect of the present invention, said first-type physical layer protocol is an IEEE 802 physical layer protocol, said second-type physical layer protocol represents one of a Synchronous and a Plesiochronous Digital Hierarchy link, and said first protocol is an IEEE 802 MAC protocol. Therein, said IEEE 802 MAC protocol represents the Medium Access Control (MAC) protocol for the IEEE 802 physical layer protocol. Said SDH or PDH link is interworked with said IEEE 802 MAC protocol to allow for a transmission of data between said base station and said radio network controller via said base station hub. This interworking may be based on a mapping table. Said second protocol operated on top of said SDH / PDH link and said IEEE 802 MAC protocol then is operated end-to-end between said radio network controller and said base station. Said IEEE 802 MAC and IEEE 802 physical layer protocols may for instance be IEEE 802.3 MAC and IEEE 802.3 physical layer protocols, respectively. The IEEE 802.3 physical layer protocol represents an Ethernet network. The use of said Ethernet network may contribute to reduce the cabling costs and the size and costs of the base station.

[0056] According to an embodiment of the second aspect of the present invention, said second protocol represents a combination of a UDP protocol and an underlying IP protocol. Said User Datagram Protocol (UDP), defined by IETF RFC 768, provides a simple, but unreliable message service for transaction-oriented services. Each UDP header carries both a source port identifier and destination port identifier, allowing high-level protocols to target specific applications and services among hosts. The Internet Protocol (IP), defined by IETF RFC 791, is the routing layer datagram service of the TCP / IP suite. The IP frame header contains routing information and control information associated with datagram delivery.

Problems solved by technology

However, with increasing numbers of transmission links (and correspondingly increasing numbers of cables and interfaces), the management complexity increases, and furthermore, compatibility problems may arise due to increasing ATM and IMA complexity.

The same problem is encountered in the context of a distributed base station architecture, as for instance specified by the Open Base Station Architecture Initiative (OBSAI) or the Common Public Radio Interface (CPRI).

Because on said Iub interface, again SDH / PDH links are most frequently used as transmission links, the same problems of increasing management complexity and potential incompatibility with increasing transmission capacity is encountered as in the case where a non-distributed base station is used.

Furthermore, due to the high data rate on the interface between the base station head and the base station body of a distributed base station, which is caused by the fact that the base band processing is performed in the base station body, a fibre connection may have to be used for this interface.

The fibre cable has to be installed by the operator, which vastly increases the deployment costs.

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